Travis Jensen details his dynamic language shootout when going through the process of switching what they code their user interfaces in.
In the end, these are the features that we felt were most important: the interaction between Java and the selected language, the IDE support, the learning curve, existing web frameworks, and the existing community support [...]
Some interesting snippets on Groovy, Rails needs Components, RIA Frameworks compared and faster WebTest (via Raible Designs). Interesting comment from one of the commenters who says:
Until Groovy stops being a random grab-bag of semi-coherent features and develops into a well-defined language with a spec, it’s not going to challenge Java in any domain other than [...]
InfoQ: What’s New in Groovy 1.5 - Groovy is starting to look pretty cool - must get round to giving it a go.